RALEIGH, N.C.  Dr. John Sampson has spent most of his career studying brain tumors. And if diagnosed with the kind of cancer now faced by Sen. Edward Kennedy, he'd pick Duke University colleague Allan Friedman for a doctor.

"He's one of the best for this type of surgery in the world," Sampson said. "If someone had to choose, he would certainly be on the top of my list."

For the delicate task of removing the cancerous brain tumor that threatens his life, Kennedy went with Friedman, a 59-year-old Chicago native is a respected leader in the field of neuro-oncology who performs the majority of such surgeries at Duke University Medical Center.

Friedman "is one of the thought leaders" in the field of neuro-oncology, said Dr. Otis Brawley, the top doctor at the American Cancer Society. An internationally known tumor and vascular surgeon, he is responsible for more than 90 percent of tumor resections and biopsies at Duke.

"He's an excellent surgeon. His patients are in very good hands," said Dr. Matthew Ewend, the neurosurgery chief at the nearby University of North Carolina at Chapel Hill.

Friedman is Duke's neurosurgon-in-chief and the program director of the university's Division of Neurosurgery. He also serves as the deputy director of the university's Preston Robert Tisch Brain Tumor Center. An internationally known tumor and vascular surgeon, he is responsible for more than 90 percent of tumor resections and biopsies at Duke.

Duke's brain tumor center was established in 1937 and has a staff of more than 250 who work only on the research and treatment of brain tumors. Doctors and staff there are currently following the treatment of more than 2,000 patients from around the world.

More than two-thirds of the adult brain tumor patients at Duke also take part in clinical trials, the university said, compared to only 8 percent nationwide.

Friedman is a graduate of Purdue University who earned his medical degree at the University of Illinois-Chicago, and did his residencies at Duke and the University of Western Ontario. His wife, Elizabeth Bullitt, is also a well-known neurosurgeon now focusing on research at UNC Hospitals, just eight miles from Duke.

Along with tumor research, Friedman is collaborating on research into epilepsy and hemorrhages in the space between the brain and the thin tissues that cover the brain.

Kennedy was hospitalized May 17 at Massachusetts General Hospital after undergoing a seizure at his home on Cape Cod. Doctors later announced the 76-year-old Massachusttes Democrat had a malignant glioma -- one of the worst kinds of brain cancer -- in his left parietal lobe.

His decision to head to Duke, a hospital with a sterling reputation, was of little surprise to his friends.

"I think he likes to conduct an exhaustive search of resources out there and then make a decision. I think that's what all patients should do," said Philip W. Johnston, a Massachusetts Democratic activist and former chairman of the Robert F. Kennedy Memorial.

This undated photo released Monday, June 2, 2008, by Duke Medical Center shows Dr. Allan Friedman, chief of the division of neurusurgery at Duke Medical Center. A statement from Senator Kennedy's office said he would be operated on Monday morning, June 2, 2008, in Durham, N.C., by one of the nation's top neurosurgeons, Dr. Allan Friedman, followed by chemotherapy and radiation. (AP Photo/Duke Medical Center)